


The Adventure of the Black Cape

by spideyxmoriarty



Category: Harry Potter - J. K. Rowling, Sherlock (TV), Sherlock Holmes & Related Fandoms
Genre: Alternate Universe - Harry Potter Setting, Case Fic, Eventual Sherlock Holmes/John Watson, Ex-Healer John Watson, M/M, Muggle Sherlock, Muggleborn John Watson, New Scotland Yard's A+ Investigations, No Smut, Not Season/Series 02 Compliant, Not Season/Series 03 Compliant, Not Season/Series 04 Compliant, Post-Season/Series 01, Story: The Adventure of the Speckled Band, Tags May Change, Wizard John Watson, because jkr doesn't respect her own canon so why should i?, but there's a magical twist, i took some minor liberties with harry potter canon, john's an excellent wizard, sherlock doesn't know
Language: English
Status: Completed
Published: 2020-08-06
Updated: 2020-12-13
Packaged: 2021-03-06 07:47:54
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 8
Words: 11,230
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25739839
Author URL: https://archiveofourown.org/users/spideyxmoriarty/pseuds/spideyxmoriarty
Summary: Disappeared from a locked room, no body, no sort of trace of a murderer or kidnapper, and all over a year ago - that did sound like a case Sherlock would love. But when you added Helen’s claiming that Julia had been killed by a cape of all things… well, that was something Sherlock would’velaughedat.ORJohn Watson left the Wizarding World after the war. He now solves crimes with his Muggle flatmate, Sherlock. But what will happen when there's magic involved in a case?
Relationships: Sherlock Holmes/John Watson
Comments: 69
Kudos: 203





	1. Prologue

**Author's Note:**

> Thanks to Steph for the beta!
> 
> [And thanks to Kittie for britpicking this story!](https://archiveofourown.org/users/KittieHill)

People celebrate in the Great Hall, but it’s not over. They cheer and jump and hug; the wails and cries of the injured silenced, too weak for anyone but the healers to notice.

Under the debris, a Ravenclaw struggles to breathe. She’s young – no older than thirteen, perhaps – and it’s a miracle John even hears her call for help. He moves the fallen bricks aside, holds her as though it’s his own life that hangs by a thread. He performs Episkey on her, tries to keep her alive as he hurries to the hospital wing.

It’s useless in the end. She doesn’t make it.

The survivors still cheer. They notice only Voldemort’s body, but not all the other ones lying in the Hall. And John decides, then, that the war, the deaths, will never have been worth it in the end. Not if no one’s learnt their lesson.

He will continue to help the ill and injured, but from now on, it will be in the muggle world.

The wizarding one has hurt him enough already.


	2. Chapter One

**Notes for the Chapter:**

> I wasn't going to post this today, but it's our favourite heale- I mean, _army doctor's_ birthday, so I decided to make an exception. Happy birthday, John!
> 
> Trigger warnings for:  
> -Helen's stepfather being manipulative and violent.  
> -Brief descriptions of corpses (they're not relevant; you might as well skip them if they make you uncomfortable).  
> -Murder. (This is a murder story. It's not _graphic_ , but I'm letting you know just in case).
> 
> Again, thanks to Steph for the beta [and to Kittie for britpicking!](https://archiveofourown.org/users/KittieHill)
> 
> PS: The next few updates will take a little longer. I'm sorry.

Afghanistan had turned out to be just like the wizarding war, the only difference being the weapons and the faces. John  _ had _ seen more predisposition, perhaps, from the muggle soldiers; but the reasons behind the war remained the same. Selfishness. Hatred. Power.

So when he got shot, it may as well have been a blessing in some way. He could start from scratch in muggle London, couldn’t he? And therapy would help, too; it had to. Muggles had better mental health services than wizardkind did.

He wasn’t entirely wrong about those assumptions in the end. But what really did the trick, the variable that truly turned his life around, was Sherlock.

Sherlock gave his life a sense, a purpose. Initially, it may have been the adrenaline that drove him to him; Mycroft had been rather correct about that.

But then, with time, it was Sherlock himself. It wasn’t just Sherlock’s brilliance, or the fact that, even though he didn’t get along with strangers, he had let John in his life in just a heartbeat. It was Sherlock’s very soul that lured John like a siren’s call.

Sure, John loved chasing criminals with him. But at the end of the day, John knew that, were it all different, were there no cases for them, he’d still be here by Sherlock.

ϟ

“Morning”, John greeted as Sherlock walked into the kitchen.

Sherlock yawned in response, sitting down at the kitchen table. He grabbed the newspaper, eyeing it.

“Trying to find a new case so soon?” John asked, pouring tea into two cups. “I’ve barely rested from yesterday’s.”

Sherlock hummed. “It  _ could _ wait a few more days”, he said. “But I was hoping there was something fun going on out there.”

John grinned.

They’d been quite busy lately. Just a few days earlier, Lestrade had called them in to examine quite a gruesome quadruple murder. The killer had burnt the victims’ skin with a blowtorch to get rid of her fingerprints. Sherlock had deemed it unimportant at first, but the case quickly escalated to serial murders, and it finally caught Sherlock’s attention when the autopsies revealed several pieces of jewellery inside the victims’ stomachs.

In the end, Sherlock was disappointed, as the killer hadn’t had any “proper reasons” (as Sherlock had put it) for her modus operandi. But the case had been solved, and that was enough for Sherlock to be in a good mood.

John sat down in front of him. He put down their food and looked up at his flatmate. “Find anything, then?” he said, taking a bite of his toast.

“Nope”, Sherlock said. “London’s too civilised lately. It’s not fun anymore”, he joked.

John chuckled. “Well, maybe we could take the day off?” he suggested. “If nothing turns up, I mean”, he clarified. “We could watch telly or something.”

Sherlock took a sip of his tea. “Perhaps. Though I still haven’t finished that experiment with the glowing fish scales”, he said, thoughtful. 

John tried very hard to suppress a chuckle. He had to admit he found Sherlock’s experiments rather exciting; but as his friend, he had to set some boundaries to assure Sherlock wouldn’t get injured or blow up the flat in the process.

“Have you seen my phone?” John asked, changing the subject. “I ought to text Louise.”

Sherlock tilted his head, gesturing towards the living room. “You left it on your chair last night”, he said. He was silent for a second, considering whether to tell John that he’d better break it off with her - she was sleeping with her landlord.

Still, he remembered how it’d gone a few months back, when he’d “warned” Molly about Moriarty. She’d been devastated, and John had berated him for being so tactless. What if he hurt John now as well? He couldn’t. He could allow himself to hurt anyone  _ but _ John.

He pursed his lips, observing him. No, it wasn’t worth it. Going by John’s face,  _ she’d _ just dumped  _ him _ . Good.

John didn’t seem very bothered anyway.

“Sherlock?” he called.

“Yes?”

“Maybe we could go out for dinner tonight.”

Sherlock smiled in agreement. Just before he could speak, though, somebody rang the bell.

ϟ

Helen Stoner sat in the living room, her knee bouncing up and down. John had handed her a glass of water, yet she had barely touched it.

She was in her late twenties, Sherlock estimated. She was wearing trainers, jeans and a speckled yellow blouse. Her hair was short and wavy, but she had covered it with a woolly hat. Odd choice of headwear in the middle of July.

“So, Helen”, John started. “Could you tell us what happened?” he asked.

Helen nodded. “My sister, Julia, died last year”, she spoke. “It was all very strange. I didn’t tell the police the truth, they wouldn’t have believed me. I just reported her missing.”

John wrote something down on his notepad. “Why wouldn’t they have?” he asked, looking back at her.

Helen sighed, fidgeting with her keys. “There wasn't a body”, she said. “They never found it ‘cause it was never there in the first place.”

Sherlock looked up at this, one corner of his mouth rising. “Explain.”

“We didn’t live together, Julia and I”, she said. “But that night, I’d had a row with my girlfriend, so I was staying at Julia’s. It was just the two of us. It was-”, she started, her voice trembling. “It was all so sudden.”

Sherlock sighed. “Yes, okay, but back to the story…”

Helen lowered her gaze towards the floor. “We were twins, you know. Identical”, she said. “We always had a sort of connection. Knowing each other’s emotions, that sort of thing.”

Sherlock rolled his eyes; John rolled his at Sherlock.

“Julia had gone to bed, and I was up in the living-room, reading. But then I felt something”, she said. “Like she was in danger. She didn’t scream or anything, but I knew something was wrong.

“I tried to open the door to her bedroom, but it was stuck. It got stuck all the time; I think it was faulty”, Helen explained. “So anyway, I ran to the kitchen to try and find something sharp to pick the lock with. But I-”

She stopped, having grown nervous as the story progressed.

Sherlock leaned forward in his chair. “Tell us what happened, Miss Stoner.”

Helen swallowed. “I saw something through the window. I don’t know what it was, Mr Holmes”, she stammered, “but it was definitely not human.”

John frowned. “Not human?” However, it overlapped with Sherlock’s voice, as he spoke at exactly the same time, saying, “What do you mean, through the window?”

Helen looked at them both, unsure which question to answer first. John gestured in Sherlock’s direction, not wanting to start an argument.

“The windows in the bedroom and kitchen open out to an inner area. I don’t really know how to describe it”, she said, dubious, “so I guess you’d better see it for yourselves. Anyway, if you look through the kitchen window, you can see the one in the bedroom.”

John frowned, struggling to picture it in his mind. Sherlock, on the other hand, seemed to understand perfectly. “Go on”, Sherlock said.

“I ran back to the bedroom and forced the door open”, Helen said, “but I found nothing. Julia was gone, there was no one else there, no weapon… nothing!”

“And you say you saw something in Julia’s bedroom? When you were in the kitchen?” Sherlock asked.

Helen nodded. “I know it sounds bonkers, but I know what I saw. It looked like… like a black cape.”

ϟ

“You don’t think she’s telling the truth, do you?” John asked after Helen had left. “For all we know,  _ she _ could be the one who killed her sister.”

Sherlock shook his head. “No, she’s not. She’s losing tufts of hair, she tried to cover it with her hat. And did you see her nails? She’s got nicotine stains all over them, she’s been chain smoking all morning”, he explained. “Besides, she hasn’t been sleeping well, she’s got dark circles under her eyes; and her knee kept bouncing up and down. She’s anxious, the memories are traumatic.”

John pursed his lips, thinking. “Maybe she imagined it? Drugs, schizophrenia?” he suggested.

“I thought of that too, but Julia’s body was never found. I’ve just texted Lestrade, see if I can get my hands on the case files.”

“Sherlock”, John tried to resonate with him. “I know you love locked-door murders, but did you hear her? She said she saw a-”

“A black cape, yes. I heard her too.”

“A bloody cape!” John exclaimed. “It’s the most ridiculous thing I’ve ever heard!”

_ It isn’t, actually _ , his subconscious reminded him. He’d seen far more senseless things. Serial suicides, a melting laptop, talking portraits, dementors... A murderous cape shouldn’t come as a surprise anymore.

But Sherlock couldn’t actually be taking her seriously, could he? Sherlock was a logical person; he would never believe such a ridiculous thing! Disappeared from a locked room, no body, no sort of trace of a murderer or kidnapper, and all over a year ago - that did sound like a case Sherlock would love. But when you added Helen’s claiming that Julia had been killed by a cape of all things… well, that was something Sherlock would’ve  _ laughed _ at.

John sighed, rubbing his temple. “Maybe it’s, I dunno, a trauma-generated memory, then”, he suggested. “Maybe Julia was killed by someone Helen knew, so her subconscious-”

“Don’t change the facts to suit your theory, John, change the theory to suit the facts”, Sherlock interrupted. “The facts so far are that Julia was never found, and Helen, being the last person who saw her, is sure that Julia was murdered by a cape.”

“But that can’t be it!” John shouted.

“It isn’t”, Sherlock said. “There’s more to it, there has to be, but there’s not enough data yet. That’s why we’re going to Helen’s flat tonight.”

_ Helen’s flat _ , right, John thought. He knew Sherlock had a point about not twisting facts, but John still found it a little too coincidental that Julia’s flat had been inherited by  _ Helen _ .

“She didn’t kill her for the will, John, stop twisting the facts!” Sherlock shouted, as though he could read John’s mind. John suppressed a smile, imagining what Sherlock’s reaction would be like if he knew about legilimency.

“Sorry”, John said instead. “And what do we do till tonight, then?”

Sherlock smiled. “Cluedo?” he suggested.

John considered it for a moment. What was the worst that could happen? It was just a game, after all; and it was definitely safer than Sherlock’s experiments. Before he could agree, though, he was interrupted by a not-so-gentle knock on the door.

Immediately afterwards, it burst open to show a man so large that he almost reminded John of Hagrid, the gatekeeper at Hogwarts. But whereas Hagrid had a kind, somewhat clumsy presence, their visitor appeared quite the opposite: beast-like, violent and ready to attack.

Sherlock, however, did not show himself intimidated, and instead remained calmly sat by the fire. John opted to do the same, but surreptitiously slipped his hand under one of the cushions to grab his gun.

“Which one of you is Sherlock Holmes?” the man demanded. John was surprised to discover he had an American accent.

“That’s my name”, Sherlock replied. “I’d ask you to tell us yours, but I don’t need to know it to know who you are.”

John suppressed a chuckle when he saw the stunned look on the intruder’s face. The latter’s surprise, though, turned back into anger in a matter of seconds. “What could you know about me?!” he demanded.

“I know that you’re Helen Stoner’s stepfather”, said Sherlock. “You followed her here, though it’s not the first time. You regularly follow her to different places.

“I know that you come from a relatively wealthy family”, he continued, “but you’ve lost a large part of your capital over the past few years, mostly because you spend a lot of it on drinking. I know that you’re violent, and you take pleasure in intimidating others, especially your family. I hope you’ll make an exception for us”, he smirked.

If Helen’s stepfather, who had yet to introduce himself, had been angry at first, he was absolutely fuming now. He pointed a finger at Sherlock. “Don’t you mess with me, Holmes”, he bellowed. “Whatever Helen told you, it’s none of your business.”

Without any warning, he turned around towards the fireplace and picked up a poker, bending it with his bare hands. “So stay out of my grip”, he threatened.

Sherlock lifted an eyebrow. “Am I supposed to be impressed?” he asked.

“I can do way worse than that”, said Helen’s stepfather. He dropped the poker onto the floor with a loud thud, and left.

“Well, that was a bit rude of him”, John spoke.

“Indeed”, chuckled Sherlock. “He left without telling us his name.”


	3. Chapter Two

**Notes for the Chapter:**

> Thanks to Steph for the beta!  
> [And thanks to Kittie for britpicking!](https://archiveofourown.org/users/KittieHill)

“I’m so sorry he did that”, Helen apologised, upon hearing her stepfather had paid John and Sherlock a visit. “I should’ve told you. He’s a bit… impulsive”, she said, opening her door and showing them in.

They’d just arrived at Helen’s flat. Luckily for their investigation, she had inherited it from Julia after her death, so gaining access wasn’t a problem.

It wasn’t very big. There was a dentist's practice just below it, on the ground floor. Upon entering the flat, they were in the living room. To the left side of it stood a small table, and against the wall opposite it was a sofa. A short hallway opened beside the table, leading to the bedroom, as well as to a bathroom to its left.

Opposite the entrance door was the kitchen, which was separated from the living room by a long counter. Indeed, just like Helen had described, there was a window there from which the bedroom could be seen. The window was on the left wall, and it opened out to an inner area, as did the bedroom window. This area was so small and narrow that it couldn’t be described as a courtyard. It seemed its only purpose was to ventilate the building and let in sunlight.

Sherlock paced from one end of the flat to the other, mumbling to himself, lost in deep thought. John knew just by seeing him that talking to him was pointless.

“What was your stepdad’s name?” John asked Helen, trying to make small talk. “He didn’t say.”

“Grimesby Roylott”, she responded.

John lifted an eyebrow. _And I thought Sherlock was the one with an odd name_ , he thought.

In the kitchen, Sherlock’s mind was racing. He couldn’t find enough clues, and it was driving him up the walls. There was more to this case; there had to be! It was obvious that Helen’s stepfather was hiding something. Why else would he have threatened them? But there was something about the man that Sherlock was not seeing. Something staring right back at him.

His mobile buzzed in his pocket. He took it out, glad to see he’d just got a text from Lestrade.

_Case closed 3 wks after reported missing._

_Legally dead._

_No suspects._

_GL_

Sherlock frowned. Just three weeks? That couldn’t be right. This was a missing person! Even with the usual incompetence of New Scotland Yard, they should still be searching for her. They couldn’t have declared her dead so soon.

He considered the possibilities. Julia’s case couldn’t have been closed just after three weeks, that alone was fishy. But it _had_ been closed, so the question was: why? Perhaps the judge had been bribed into it. After all, it wouldn’t be the first time the justice system was corrupted.

Then there was Helen’s stepfather. Although it didn’t fit with Helen’s claims about the cape, Sherlock could still tell the man knew something about the circumstances of Julia’s disappearance. And not only did he know, but he had threatened Sherlock, who he knew was a detective. He was definitely trying to keep the truth from surfacing.

“The plot thickens”, Sherlock said under his breath.

“Did you say something, Sherlock?” John asked.

Sherlock cleared his throat. “Nothing of importance, really”, he said, walking into the living room. “You’ve kept Julia’s furniture, have you?” he asked Helen.

“Well, yes”, Helen said. “After Persia and I broke up, she kept everything, so it was good Julia’s things were still here.”

“Who?” John asked.

“My ex", Helen smiled, somewhat shyly. “I must've mentioned her. We broke up about a month after Julia died", she said. She turned to Sherlock. "Have you found anything, then?”

“I’ve got a theory”, Sherlock answered. “But John and I would have to stay the night to test it.”

John frowned. What good would that do?

“Oh”, said Helen. “Alright.”

“I’m afraid we’ll have to borrow your bedroom, though”, Sherlock explained. “I want to recreate the circumstances of Julia’s disappearance as accurately as possible. You’re to stay in the living room.”

Helen flinched. _Of course_ , thought John. She wouldn’t want to relive such a traumatic moment. God only knew how much courage it had taken her to even ask them to investigate.

“Sherlock”, he called. “Maybe there’s another way?”

Sherlock shook his head. “It’ll have to be like this.”

Before John could stop him, Sherlock turned around and went into Helen’s bedroom, not saying another word.

John smiled at Helen, apologetic. “If you, er, need anything, just let us know.” And with that, he too walked away.

“What the bloody hell was that all about?” he asked as soon as he’d closed the door.

“Hm?”

John sighed. “You can’t just tell her you’re going to make her relive her sister’s death and act like it’s nothing”, he said.

“I said ‘disappearance’, not ‘death’”, Sherlock corrected.

“That doesn’t matter!” John shouted, exasperated. “To Helen, she’s dead, so you’ll respect that”, he ordered. “And you’d better explain that brilliant plan of yours, because I don’t see how we’re going to get a bloody cape to come here and try to kill us.”

Sherlock rolled his eyes. “We won’t make it come. It will do that on its own”, he said.

 _Merlin’s beard_ , John thought, _if the cape doesn’t kill him, then I will._

“Care to elaborate?” he asked instead, his tone of voice suggesting his patience was wearing thin.

Sherlock grunted, burying his face in his hands. He hated having to explain everything. Most people never understood, no matter how many times he repeated himself, and it drove him mad.

But then again, John wasn’t most people. John would put up with Sherlock when everyone else would call him a nutter. John would be patient with him when he was a bit ‘not good’. And yes, perhaps John couldn’t deduce things at a glance like Sherlock could, but he _tried_.

John was different. That was why Sherlock trusted him in the first place.

“Whatever happened to Julia, Helen witnessed it”, Sherlock said. “The most logical hypothesis would be that someone wearing a black cape came here and murdered her. Perhaps they wore it to avoid being recognised. It’s unlikely, though, because why would they conceal themselves if they thought Julia was alone?” he asked, more to himself than to John.

“Still, however it happened”, he continued, “they got away with it. The case is closed, which takes me to the next important question”, he paused. “If Julia was reported missing, the police should still be searching for her. But they stopped investigating after three weeks; they declared her dead.”

John frowned. “Just three weeks?” he asked, confused.

“Exactly!” Sherlock exclaimed. “So it’s been covered up. Besides, Helen’s stepfather is hiding something. That’s why he threatened us”, he explained.

“You suspect him?” John asked.

Sherlock smirked. “Perhaps”, he said. “And if he got away with murder once, what makes you think he wouldn’t try again?”

“To keep Helen silent”, John murmured, understanding Sherlock’s point. “So that’s the plan. We stay here and see if Roylott tries again?” he asked. “What if he doesn’t? What if it wasn’t even him who killed Julia?”

“Then we won’t have lost more than a night”, Sherlock replied. “We can think of a different theory in the morning.”

They were both silent for a while. There wasn’t much they could do, really, and John supposed they would just have to wait.

His gaze fell upon Sherlock, sitting there on Helen’s bed, lost in a sea of deductions and speculations. To that day, John still found himself marvelling at Sherlock’s brilliance. He had been captivated by him as soon as he’d met him. But instead of diminishing over time, the admiration John had for him just kept growing.

He was hooked. Sherlock was like unicorn blood: he had saved him so many times, and in so many ways, and now John couldn’t let go.

“You can sleep, you know”, Sherlock spoke suddenly. “I’ll wake you up if something happens.”

John frowned. “Why would I want to sleep?”

“We had a complex case yesterday, you said you’d barely rested from it”, Sherlock said.

John chuckled. “I’m fine, don’t worry”, he said. “Besides, if there really is a killer cape out there, I wouldn’t wanna miss it”, he half-joked.

Sherlock laughed at this. Soon they were both giggling, unable to stop themselves. The idea of a cape murdering someone was so ridiculous, and yet here they were, awaiting it in a client’s bedroom. It was impressive how they always managed to get into the most bizarre situations.

The giggles eventually died out, and the minutes stretched into hours. The clock struck midnight, then one, then two… John was beginning to wonder whether he _should_ go to sleep, when he saw it.

It was larger in size than John would have imagined, but he recognised it at once. A Lethifold. It was sliding under the window, but it wasn’t touching the wall - instead, it glided above it. The beast’s skin was jet black; and had John been a muggle, he too would have easily mistaken it for a cape.

He was suddenly glad he had put an extensive charm on his pocket, for now he could reach into it and grab his wand. He realised Sherlock would see, but right now, he didn’t care. He had to protect him. John stepped in front of Sherlock, shielding him, and shouted:

“Expecto Patronum!”

They were momentarily blinded by the brightness of John’s Patronus. It came out of his wand with ease - unlike Dementors, Lethifolds didn’t make it hard to cast the Patronus Charm - and it was shaped like a hedgehog. Despite its small size, it was effective: the Lethifold slid back underneath the window, fleeing.

Sherlock did not understand.

A million questions crossed his mind, overlapping. He tried to catch up with his train of thought, struggling to comprehend what had just happened - he didn’t even know where to begin.

Whatever had come into the bedroom did resemble a cape, like Helen had described. But it hadn’t been one. It was different. It was _alive_. It was monstrous, eerie, _unknown_. That was what terrified Sherlock the most: he had no name for what had attacked them.

And still, he could’ve tried to find a thousand explanations for it. He could’ve blamed it on drugs, or fear… but there was one thing which he could not account for:

John.

Even though Sherlock refused to admit what John had done, there was only one way to describe it: magic. John had done _magic_. He had pointed a _wand_ at the beast; he had cast a spell upon it. _Expecto Patronum - ‘I await a guardian’._

Before Sherlock stood the man he most trusted. The person he loved and valued the most in the world. And yet, in the blink of an eye, he had turned into a complete stranger.

**Notes for the Chapter:**

> I know the hedgehog's a bit cliché, but I had my reasons to choose it as John's Patronus. [You can learn more about John's Patronus (and other common Patronuses) here!](https://wizardingworld.com/features/what-your-patronus-says-about-you)


	4. Chapter Three

**Notes for the Chapter:**

> As always, thanks to Steph and [Kittie!](archiveofourown.org/users/KittieHill)

John closed his eyes.

Behind him, Sherlock was so silent it was as though he had stopped breathing. And though John was no expert in legilimency, he could still sense every emotion that crossed Sherlock’s mind. Confusion. Fear. Doubt.

John supposed, in the end, he hadn’t had a choice. The only known way to repel a Lethifold was through the Patronus Charm. No other spell, nor Muggle weapon of any kind, would've had any effect on the beast.

He sighed. There was no avoiding this. Opening his eyes, he turned around, hands held up to show he meant no harm.

“John”, Sherlock whispered. His eyes were open wide, examining John as though they were seeing him for the first time. He covered his mouth with shaking hands, unknowingly attempting to conceal the fact that he could not find his words.

“I’m sorry”, John said, trying to keep his voice from trembling. “I promise, Sherlock, I’ll explain everything, but I need you to trust me on this.”

Trust him? How could he _trust_ him?

John had lied to him. All the time they'd known each other, John had lied about who he was, about his past. He hadn't confided in Sherlock enough to tell him that he could do magic, but now he asked Sherlock to trust _him_?

Sherlock refrained from saying it aloud, though. This was not the moment to argue; they were in the middle of a case. They had to work together. Instead, he tried to deduce as best as he could with the little information he possessed. It was the only thing he could do to overcome the shock.

Whatever had attacked them fit Helen’s description. It must’ve been what killed Julia, and now it had come to kill Helen as well. It wasn’t anything like Sherlock had ever seen before, and John had driven it off with _magic._

John had never done magic in front of Sherlock. He would never have exposed himself like that if it hadn’t been a matter of life or death. Therefore, it was safe to assume that the creature was magical too. If it hadn’t been, John would’ve shot at it with his gun, wouldn’t he? Magic must’ve been the only way to fight it.

“What was that?” Sherlock asked, trying his best to maintain his composure.

“A Lethifold”, said John. “It’s a magical beast, it suffocates people and eats them. They also call it a Living Shroud”, he explained. “But they’re not common in Britain, they’re tropical. Why would it be here?” he mumbled.

“Someone must’ve brought it here”, Sherlock reasoned. Suddenly, he gasped, saying, “Roylott. He’s in on it, remember? He was hiding something."

John looked at him, confused. “You think Roylott’s a wizard?” he asked. “He can’t be, I would’ve met him before. Wizarding communities are very small”, he said, frowning. He sat down on the bed, head in his hands. “No! Wait!” he exclaimed suddenly, looking up. “He’s American. If he moved here after I left the wizarding world... He _could_ be a wizard”, he realised. “Sherlock, you’re a genius!” he smiled.

There were a lot of things Sherlock still didn't understand; so having figured out something along this mess was good – better than good. He smiled back at John.“What do we do now?”

John sighed. “First, we’ve got to make sure Helen will be safe.” He stood up and walked to the door, only to find it locked. Just like it had been when Julia died.

“Alohomora”, John said. The door opened. He put a finger to his lips, signalling for Sherlock to keep silent, and whispered, “Intrusus Revelio.”

Nothing happened. Roylott wasn’t there. Peeking out the door, John was glad to see Helen still asleep on the sofa. This was good. They could keep her in the flat; she wouldn’t know a thing. She would be safe.

Sherlock watched as John raised his wand and began to cast different spells. It was so strange to see him do so. Sherlock couldn’t help but stare, mesmerised. The traces of John's wand upon the air were elegant, and from his mouth emanated all sorts of enchantments, which would’ve been foreign to Sherlock’s ears had he not known Latin. _Salvio hexia. Protego totalum. Repello Inimicum._

_They’re protective spells_ , Sherlock realised.

“Sherlock”, John called, interrupting his thoughts.

“Hm?”

“I asked, where could he be? Roylott”, John repeated. “We’ve got to find him. Now.”

Sherlock pressed his lips. The beast had come in through the window, and assuming Roylott had been there to let it loose… God, he hoped he could assume that. He didn’t know the limits of magic. Still, the balance of probability was Roylott couldn’t be too far. He had to be close, he…

_Oh._

“Sherlock?” John called again.

“Downstairs”, Sherlock exclaimed. “The dentist’s practice, remember? I paid it little attention earlier, it didn’t seem too important. It’s Helen’s mother’s! Dolores Stoner! It would be the easiest thing for Roylott to sneak in there and let the beast out through the back window", he explained. "A window _right below Helen's_."

John nodded. "Great", he said. "Right. I, er…" he sighed. "We have to take him by surprise. If we don't, he'll escape." He paused, twitching his wand in his hand. He looked back up at Sherlock, somewhat nervously. "Do you trust me?"

"John-"

_"Do you trust me?"_

Sherlock nodded.

Suddenly, John's hand was holding his, and before Sherlock could even begin to ask, he felt his whole body contort. It bent in all directions, his eyes sinking into his skull, his arms stretching out. It was as though he was being sucked by a vacuum cleaner. And then…

They were downstairs.

ϟ

_Are you okay?_ John mouthed, holding Sherlock by the shoulders. The latter gulped, still confused, but nodded nonetheless.

John realised, in retrospect, appareating into the practice could've gone wrong. Very wrong. Sherlock could've splinched himself. And if Roylott used that to his advantage…

He shook his head. They were alright. They had to go on. _In for a Knut, in for a Galleon._

He passed Sherlock his gun. While it was true that it wasn't the best weapon against magic, he needed Sherlock to be able to defend himself.

The practice was about as large as Helen's flat. They were close to the entrance door. Roylott was nowhere to be seen. John signalled for Sherlock to stay behind, and he approached the back of the practice, wand at the ready.

Sherlock hated it.

He hated this whole situation. He felt useless. What good was he here? He couldn’t do magic. All he had was a gun. He couldn’t even use his intellect in their favour - he knew nothing about spells or magical creatures or bloody _teleportation_. The margin of error in his deductions was abysmal.

Suddenly, he was startled by a loud metallic clank coming from the back room. Someone had dropped something - dental tweezers, judging by the sound. Probably they’d stumbled upon them. They must’ve been startled, taken by surprise... 

_John._

Sherlock ignored all of John’s warnings to stay behind. He couldn’t risk it. John was in danger. If something happened to him…

He cocked his gun and ran. Just like he had suspected, he found Roylott, wand pointed at John.

“Expelliarmus!” Roylott shouted.

A red light came out of the tip of his wand. John’s flew away from his grasp, and Sherlock lost it. In one swift move, he fired. Roylott fell to the floor, blood dripping from his forehead. He was dead.

“Are you alright?” Sherlock asked, dropping his gun aside and searching John for injuries.

“I’m fine”, John assured. “I’m fine, Sherlock, really!” he repeated when Sherlock kept checking him. “He just disarmed me. I’m okay.”

Sherlock sighed. “I was so worried”, he said, voice almost trembling. “I didn’t know what he could do to you, I… I was scared, John.”

John looked him in the eyes, surprised at Sherlock’s confession. “You’re not mad at me?”

“Why would I be?”

John looked away. “For not telling you… that I’m a wizard.”

Sherlock bit his lip. “I can’t deny I’m surprised you didn’t trust me with your secret”, he admitted.

He meant it. He’d known John for almost two years now. And he had noticed that John was different from most people, but… he’d thought it was just one of his quirks. He had not suspected for one second that John could be hiding something as big as this from him. He was his best friend. Sherlock had thought John trusted him.

He had been wrong, he supposed.

“Sherlock…” John begged. “Believe me, if I had told anyone, it would've been you. I just…” he paused. “I couldn’t. The wizarding world… it’s bigger and more complex than you can imagine. There’s a statute of secrecy. So many laws and measures… I wasn’t _allowed_ to tell you.”

Sherlock nodded, slowly taking that in. "So what do you do now that I've found out?" he asked, not sure whether he wanted to know.

"I… I have to obliviate you."

**Notes for the Chapter:**

> Sorry that this chapter was a little shorter than the previous ones, but I did it for the cliffhanger. Sorry about the cliffhanger as well.


	5. Chapter Four

**Notes for the Chapter:**

> Special thanks to [Kittie](archiveofourown.org/users/KittieHill) for britpicking this chapter, and to Steph for betaing it! I'd be lost without them.

Mycroft had warned him.

John could still remember it. The very night he had shot the cabbie, Mycroft had called him aside from the crime scene. Looking back, John supposed he should have expected him to figure it out within seconds. But that night, he had taken him by surprise.

"Why did you leave Wizarding Britain, Dr Watson?" Mycroft had asked.

John had clenched his fist. "How do you know that?"

Mycroft had smirked. "I occupy a minor position in the British government. It was easy enough to access all of your legal documentation."

"Only the Prime Minister is allowed to know about wizards."

"As are a few other people, including myself", Mycroft had remarked. "My brother seems very fond of you, doctor", he'd said, "so I'll give you a piece of advice. Don't perform magic anymore."

John had scoffed. "I'm not stupid, I wouldn't do that in front of him. He's a Muggle."

"I mean, don't _ever_ perform magic", Mycroft had clarified. "Sherlock doesn't miss a detail. Should you cast the tiniest spell miles away, he would know something was off. I don't think he'd jump to the conclusion of magic… but I wouldn't risk it if I were you."

John had pressed his lips. "Why are you telling me this?"

"You seem to be as fond of Sherlock as he is of you", Mycroft had responded, "and I think it would be a pity for him to become so lonely again."

God, he’d been so right.

Looking at Sherlock now, telling him he had to obliviate him… it seemed impossible to do. How could John gather enough courage to wipe Sherlock’s memories of magic? How would he look him in the eye when they were back at Baker St and not let the guilt show on his face? How many times would he have to Confund him from now on, whenever Sherlock realised there were blanks in his memory? He couldn’t. He couldn’t.

But he had to.

Sherlock stepped back. “Obliviate me?” he asked. “What does that mean?”

John took a deep breath. “I have to wipe your memories”, he said, barely audible. “I’m sorry, Sherlock, I really am”, he apologised. “But we’re only allowed to tell family. Partners, relatives… Not friends.”

There was something in Sherlock’s expression that John couldn’t quite put his finger on. He would’ve said he looked sad but… that wasn’t it. It wasn’t just sadness. Was it anger? Denial?

Finally, Sherlock opened his mouth. “What if I weren’t your friend?”

John blinked. Was Sherlock trying to get away from him? Was he really so mad at him? “Sherlock…”

Sherlock continued, not letting John speak. “What if I were… your partner?”

Ϟ

It was the only way. Sherlock knew it was risky to ask. While he _had_ had his suspicions about whether John loved him back, it was also true that he could've got it wrong. But what else could he do? He didn't want John to hide himself from him anymore.

Perhaps Sherlock didn't understand magic or the seemingly underlying cultural differences between wizards and non-magical people. But he _wanted_ to. Magic was a part of John, as much as were the little crinkles by his eyes or his questionable taste in jumpers; and Sherlock wanted to embrace every single detail about him.

He loved John. He couldn't let him go.

“I… I didn’t know you felt that way”, John spoke, after what had seemed centuries.

Sherlock smiled, shyly, tenderly. “I was always afraid to tell you”, he confessed.

John chuckled fondly, taking Sherlock’s hands in his. “I’d love to have you as my partner”, he smiled back.

His words were honest. He had tried to suppress his feelings for Sherlock for so long, thinking they were unrequited. He had spent so many nights dreaming of holding Sherlock, kissing him, sharing every bit of his soul with him. And now here they were, finally together, like they deserved to be.

He somehow wanted to be angry at Sherlock for not having said anything, or at himself, for not having realised sooner. And yet, in this moment, how could he feel anything but joy? 

“What now?” Sherlock asked suddenly.

“Hm?” John asked. He’d been too lost in his thoughts.

“Shouldn't we try and find the, er, beast… thing?”

John chuckled. “The Lethifold”, he corrected. “I dunno. I'm not qualified to deal with those things.”

Sherlock frowned, confused. “But you… you did. In Helen's flat.”

“Yeah, well, I got outstanding N.E.W.T.s in Defence Against the Dark Arts”, John said, shrugging. “But we’d better just let the Ministry handle it.”

Sherlock sighed, not understanding a word. “Could you say that again but in English?”

John smiled. “I'll buy you books about magic, I promise. It's too much to explain in just one night”, he said. “By the way, d'you know where my wand went?”

Sherlock looked around. “There”, he said. “Next to that cabinet.” He walked towards it and bent down to pick up John's wand. 

Suddenly, he felt disoriented. What was he doing here? He was sure he had to be somewhere else. Hadn't Lestrade called earlier? Damn it, yes, he'd phoned and said to drop by the Yard. Something about paperwork… couldn't wait…

Sherlock stood up. “I've got to go”, he said hurriedly, already heading to the door.

John frowned. “Go where?”

“Scotland Yard. It's urgent”, Sherlock responded.

Suddenly, John understood. He picked up his wand and shouted, “Colloportus!”

“What did you do that for?!” Sherlock complained, noticing the door was locked.

“The cabinet, it's got a Muggle-repelling charm”, John explained, far too calm for Sherlock’s liking. “It made you _think_ you had something urgent to do. You don't.”

Sherlock felt as though he would get wrinkles on his forehead if he kept frowning so much. “It _what?”_

“Just… stay here, okay?” John commanded.

He came closer to the cabinet, wand still in his hand. Pointing it at the padlock, he spoke, “Alohomora.” The cabinet door unlocked. Clearly Roylott hadn't thought to protect it from wizardkind. He must've thought he only needed to worry about Muggles.

John opened the door and peeked in. Inside the cabinet was a long ladder, which led to some sort of underground office. He couldn’t see much farther, but the place seemed to be huge. It was clear Roylott had used an Extension Charm.

He got on his knees and closed the door. They needed help.

“John?” Sherlock called. “What is it? What’s going on?” he inquired, looking at John with confused eyes.

John cleared his throat. “The cabinet’s bigger on the inside. I think the Lethifold might be in there”, he said.

Sherlock’s eyes opened so wide they were nearly popping out of their sockets, and his pitch rose by a few octaves. “ _THE CABINET IS–_ ”

“Bigger on the inside, yes”, John repeated. He sighed. He realised he would have to contact the Ministry; and if he had to be honest, he would rather have drunk three pints of Polyjuice Potion. “Look, Sherlock, I wish I could explain everything to you right this instant”, he said, “but I have to go down to the Ministry. We need help.”

“What Ministry?” Sherlock asked. He was almost begging John to be clearer at this point. There was so much he still didn’t understand. And yes, Sherlock knew it was too much to learn in one night – it hadn’t even been an hour since he’d found out about magic, for God’s sakes. But John kept using all these strange terms, like _Lethifold_ and _Muggle_ , instead of just paraphrasing things; and it really wasn’t helping.

“The Ministry of Magic.”

“You mean you’re going to the police? John, there’s a carnivorous demon in there, for God’s sake! There isn’t time to talk to the police!” he exclaimed.

John took Sherlock by the shoulders. “I’ll be right back, okay? Ten minutes at most”, he smiled, trying to reassure him.

“What if it comes back?” Sherlock asked. “The beast.”

John's expression turned sombre for a second, but he quickly managed to hide it. He pointed his wand at Sherlock (or, technically, poked him with it, since they were standing so close to each other) and said, “Protego totalum.”

Sherlock had expected it to hurt, to be unpleasant in some way; but in reality, all he felt when John enchanted him was a tickling sensation.

John smiled at Sherlock, cupping his cheek with one hand. “I love you”, he whispered.

“I love you too”, Sherlock whispered back.

Stepping back, John vanished in the air.


	6. Chapter Five

**Notes for the Chapter:**

> PLEASE READ NOTES:
> 
> Hello!  
> I'm so sorry it's been so long since the last update. I've had a lot less free time since uni started. Besides, I had to rewrite this chapter from scratch about four different times because I didn't like it, and I didn't want to post anything until I was 100% sure I liked it.  
> Also, this fic is almost coming to an end. There will be one more chapter and possibly an epilogue.  
> I'll probably write a short sequel. And who knows? I might write more of this ficverse after that as well. Please let me know if you'd be interested in reading that!  
> As always, a huge thank you to Steph and Kittie! I couldn't do this without their help.

Ten minutes allowed a lot of thinking, Sherlock decided. Especially now that the immediate danger had passed.

He was still trying to process everything that had just happened. There was so much he didn’t understand. And Sherlock loathed not understanding things.

He could read people’s entire lives just by looking at them. Whether they were married, what kind of job they had, whether they liked it, where they had been the night before… It was all displayed in front of him like a painting at a museum.

But magic? Magic was a kind of art Sherlock did not know. It was Picasso: unpredictable, strange. Every stroke of the brush was there, in the right place, but still not where one would have expected it to be.

Sherlock supposed magic must have had its logic. But how to unravel it? He was lacking so much information. How did it work? Where did it come from? Could it be learnt? Could he, too, perform magic if it was taught to him?

He sighed, ruffling his curls. He wouldn’t find answers to his questions by just sitting there.

His gaze fell on the cabinet. Sherlock wanted to step inside it. He was eager to know more, to see more; and how would he ever solve the case if he didn’t go further? If he could just look inside, he could find clues. But he remembered what John had said: the cabinet was enchanted, and if Sherlock got close to it, he would grow confused – again.

He drew his hands to his chin, thinking. According to John, the spell was meant to repel _Muggles._ While Sherlock didn't know the word's exact definition, he deduced it must have meant non-wizard folk – after all, the spell had only affected _him_ , but John had seemed immune to it. The question, now, was this: could _objects_ be repelled?

Ϟ

Less than five minutes later, Sherlock had come up with a solution.

It was fairly simple, really: to open the cabinet, he pulled the door using a mop, which he had borrowed from the janitor’s closet. He had taped his mobile to one end of the mop, opening the camera to record. That way, he could use it to peek inside without having to come closer.

_Maybe I can’t take a look_ , he thought, _but at least my phone can._

He hadn’t stood there long, waiting, when a small animal climbed up from inside the cabinet. It had black hair and what looked like a duck bill. Sherlock wondered, for a brief instant, whether it was a platypus; but he soon disregarded the idea. Platypi had longer, flatter bills, and slightly fairer hair. This creature, on the other hand, was furrier, and its hair was much darker and its bill less flat than a platypus’s.

Sherlock stared at the animal, open-mouthed, as it casually took his mobile and slipped it into a pouch on its belly.

“Oh, no, you won’t”, Sherlock said between gritted teeth. He began to pull the mop slowly, trying to bring the creature closer without scaring it away. He was almost there, he could almost grab it, and…

“WHAT THE _HELL_ ARE YOU DOING?"

Sherlock dropped the mop abruptly. The animal, startled, sneaked back inside the cabinet.

John was standing right behind him. His jaw was clenched, and his grip on his wand was so tight that it seemed as though it would break any second.

“I was looking for clues”, Sherlock explained.

“Looking for… ARE YOU OUT OF YOUR MIND?!” John cried. “I leave you here for ten minutes, TEN MINUTES, and your first instinct is to go searching for a beast that could kill you on the spot! Do you even realise how dangerous that was?!”

John couldn’t believe it. What in the name of Merlin had Sherlock been thinking? If the Lethifold had attacked him, he would’ve had no way to defend himself. He could have _died_. And it would’ve been John’s fault, because he had left him there, alone.

John could never have forgiven himself if something had happened to Sherlock before he returned. In fact, he had been sick with worry since he'd left for the Ministry. Of course, if he had gone there for other reasons, he still would’ve been dying to run away. To go back home, away from that society he no longer felt a part of. But that night, knowing there was a bloody Living Shroud wandering around Muggle London, perfectly able to kill Sherlock within minutes, John had hastened through the Ministry like a bat out of hell.

Sherlock gulped. “I just wanted to help”, he said, barely audible.

John sighed, doing his best to calm down. “I know you did”, he said. “But… Sherlock, you can’t defend yourself against a Lethifold. What if it had escaped when you opened that door? I could’ve lost you”, John said softly, putting a hand on Sherlock’s cheek. “Please don’t ever do something like that again.”

Sherlock looked down. “I'm sorry", he muttered.

John lifted Sherlock’s chin, making him look John in the eye. “It’s alright”, he said. “Now, listen. There’s a patrol on the way; they’ll be here any second. I need you to be nice, okay? Please”, he added. “For me.”

Sherlock had no time to respond, for right then, three people teleported into the practice.

Two of them were women, one in her late twenties and the other no older than thirty-four. There was also a man around John’s age whose face and neck were full of scars. They were all dressed in identical black cloaks; which, although it was obviously a standard uniform, Sherlock found rather odd. Who in their right mind would wear a _cloak_ in the 21st Century?

“Help’s here”, John said to Sherlock, awkwardly.

“Indeed”, said the male officer. He looked at Sherlock. “And you are…?”

Sherlock extended his hand. “My name is Sherlock Holmes; I’m Dr Watson’s partner”, he announced smugly.

“Partner?”

“Boyfriend”, clarified John.

The officer shook Sherlock’s hand. “HW Septimus Loptson”, he introduced himself.

Sherlock nodded, resisting the urge to ask what exactly _'HW'_ meant. The fact that he barely understood wizarding terms did not mean that he wanted to look like an idiot.

“Now, if you two don’t mind”, Loptson said, rubbing his hands somewhat excitedly, “we’ve got a beast to catch.”

The three officers went down the cabinet, and Sherlock did his best not to rub his eyes at the sight of it. He was still struggling to believe that a simple piece of furniture could actually be _bigger_ on the _inside_.

Suddenly, he felt John’s hand on his shoulder, calling him back to his senses. “You okay?” John asked.

Sherlock nodded. “Yeah, I just… I’m okay”, he half-lied.

The corners of John’s lips rose slightly as if to encourage Sherlock. “Well, c’mon”, he said, gesturing towards the cabinet. “Unless you wanna miss the fun”, he smirked.

But Sherlock remained immobile, staring blankly at the cabinet. John frowned. They had to go after the Lethifold, they had to find more clues. Why wasn't Sherlock coming?

"Sherlock?" John asked, somewhat worriedly. "What's wrong?"

“I… I can't go in", Sherlock muttered. "It's got that… charm… thing", he tried to explain, struggling to find the right terms.

John's lips formed an _O_ as he realised what Sherlock meant. Of course, John should've remembered the Muggle-Repelling Charm. He smiled at Sherlock encouragingly. Then, he pointed his wand at the cabinet, and said, "Finite Incantatem."

"There", he said to Sherlock. "We're good to go." He gestured for Sherlock to follow, and began to climb down the ladder.

Truth be told, John wasn't as comfortable with this case as he was trying to make Sherlock believe. He had had no contact with the wizarding world in over a decade, and he had no intention of going back. It brought back too many painful memories.

And besides, John didn't feel welcome among wizards. Being muggleborn, he had been terrified during the war. Every day, he would wake, not knowing if he would live to see the sunset; not knowing if Harry and his mum were still alive. And even when the war had ended, John hadn't forgotten: hatred was still present. It was still out there, pumping through the veins of every blood supremacist, even those who hadn't joined the Death Eaters.

So now, being forced back into the wizarding world, John was desperate to get away. 

As they made their way down the ladder, the place grew darker and darker. In fact, there was barely any light at all. Sherlock instinctively reached into his pocket for his mobile, so that he could turn on the flashlight; but then he remembered that a creature had taken it from him. Luckily, however, John seemed to catch on, and so did the other wizards: almost in unison, they whispered, “Lumos.”

Immediately, the tips of their wands illuminated, and the place came into view. Scattered all around were cages of all sorts and sizes, each containing magical creatures, most of which looked like they had gone days without eating. Sherlock ignored the names of most of them, but there were some, such as unicorns and dragons, which he vaguely recognised from folklore.

_Dragons?_ he thought to himself. He was no expert, but they certainly looked dangerous. Sherlock didn't think a dragon was the kind of animal you could buy at a pet shop.

And then he realised: these creatures must all be illegal – or quite hard to get one's hands on, at least. They were trapped in cages in a magically-concealed cabinet, so that they couldn't escape or be found. That could be no coincidence.

Sherlock gasped, smirking as the answer became obvious to him:

“He was a smuggler.”

**Notes for the Chapter:**

> Septimus Loptson is a minor OC that I created for this fic. Feel free to make a deduction about him in the comments! I left some clues ;)


	7. Chapter Six

**Notes for the Chapter:**

> TRIGGER WARNING: Discussions of Domestic Abuse
> 
> Special thanks to Steph for betaing and to Kittie for britpicking!

_A smuggler_.

It made sense, now that John thought about it. How else could Roylott have got hold of a Lethifold? It was one of the most lethal beasts in the world; no one could have laid their hands on one without breaking a few laws.

But Roylott… Roylott had dozens, perhaps hundreds of creatures, all within arm’s reach. And the Lethifold was ideal: a killer beast that left no trace of its presence. Julia would’ve stood no chance against it, being a Muggle.

“Well, this will take a _lot_ of paperwork at the Ministry”, Loptson commented humorously. “But back to the Living Shroud. Naja, you go left; Fernández, you go right”, he instructed the other officers. “I’ll check the back. And John”, he said, “let us know if you see anything.”

“Ta, Sept. I will”, John replied.

He turned his gaze to Sherlock, who was frowning, his hands pressed against his mouth as though he were praying. John knew that gesture: Sherlock was trying to deduce something.

"Sherlock?" he called. "What's wrong? What are you thinking about?"

Sherlock murmured something, almost inaudibly.

John frowned. "Come again?"

"He _trapped_ her", Sherlock repeated. "John, could he have locked her door using magic?"

John scratched his neck, thinking. "It'd take a bit of practice to do that from downstairs”, he said, “but I don't see why not."

Sherlock nodded. He seemed to be onto something that John couldn't yet see. It was truly impressive, John had to admit, how Sherlock was handling the case. He knew almost nothing about magic, and yet, here he was, figuring everything out as though he had studied at Hogwarts himself.

"We have to talk to Helen", Sherlock said. "Now."

John raised an eyebrow. "I'm sorry, talk to her?” he repeated, bewildered. “Sherlock, she's a Muggle, we can't tell her anything about this!"

"Why not?" Sherlock demanded. "She's our client."

John sighed. "We have to obliviate her after we're done here”, he explained. “I told you, there's a Statute of Secrecy."

"What if she already knows something?" Sherlock asked.

John frowned. "What?"

Sherlock sighed, clearly frustrated by having to explain. "You said you lot can tell family, can't you?" he asked. "Roylott was her stepfather. Helen might _already_ know about wizards."

Ϟ

No matter how many times John did magic, Sherlock didn’t think he’d ever get used to it.

They were standing outside Helen’s door. Sherlock had suggested that they knock, but John had responded, far too calmly, that if he didn’t remove the protective charms first, they’d disintegrate as soon as they crossed the door.

 _Magic really makes no sense_ , Sherlock thought to himself.

“Okay, that should do,” said John when he was done. He rubbed his wand in his hands, then pointed it at the handle. “Alohomora.”

The door opened.

The flat was eerily quiet; no sound but the electric hum of the fridge and the ticking of a clock. John and Sherlock stepped inside, trying to make as little noise as possible so as not to startle Helen, thinking her asleep. But as John approached the sofa to wake her up, he realised she was not there.

This couldn’t be good. He took a deep breath, telling himself not to let worry affect him. She might have simply got up to go to the toilet; she was probably alright. But, deep inside, he wondered. Had they been too late? Had the Lethifold, perhaps, found its way back to her flat?

“Helen?” John called. “Are you there?”

“Oh, thank God you’re okay!” came Helen’s voice from the bedroom, and John sighed with relief. She rushed towards them. “I was so worried!” she said, her voice shaking, as though she was about to cry. “I heard noises, and then I couldn’t find you anywhere, and I… I thought that thing had killed you both.”

John smiled at her reassuringly. “Don’t worry, we’re fine.”

“We do need to ask you some things, though”, Sherlock interrupted.

Helen blinked. “What… what do you mean? I’ve told you everything I know, I-”

“No, Miss Stoner, you haven’t”, Sherlock responded.

It was then that Helen noticed the wand in John's hand. Her eyes went wide open, the pieces clicking into place, though she seemed rather confused. "You're a… a-"

"A wizard", John completed.

Sherlock sighed. "Yes, obvious", he rolled his eyes. "Now focus! Miss Stoner, I need you to tell us everything you've omitted so far. Including Mr Roylott's being a wizard."

Helen nodded slowly, moving towards the sofa and sitting down. John and Sherlock followed.

“I don’t actually know much”, she started. “Grimesby married Mum when Julia and I were sixteen, so I guess he was… forced… to tell us. Didn’t really have a choice; we were all living together.

“But he’s always been very secretive about it”, she continued. “We never found out what he does for a living, or how magic works. All I know is he threatened us with magic constantly”, Helen sighed. “He still threatens me, even though I moved out years ago.

“Julia was always trying to convince Mum to leave him. I used to do the same, at first; but I gave up after a while. It was pointless”, she explained. “Mum always says she can’t; says he’s gonna hurt her if she even thinks about it. And what could I do? What could Julia have done?” she asked. “We couldn’t tell the police our stepdad was a dangerous wizard; they would’ve thought we were mad.”

Sherlock drew his hands to his chin. “Did Julia ever stop asking your mother to leave Roylott?” he inquired.

Helen shook her head. “I don’t think so”, she muttered. “She and Mum argued a lot because of that, actually. Although”, she added, “they were starting to settle their differences not long before Julia died. I remember her saying.”

“What about this flat, then?” Sherlock asked. “Wasn’t it hard for Julia, living upstairs from your mother’s practice?”

“I don’t know”, Helen said. “I suppose so. It was a present from Grimesby; Julia only accepted it so she wouldn’t have to worry about rent while finishing her studies”, she explained.

Sherlock smirked, evidently having connected the dots. John, on the other hand, fidgeted with his wand, not quite following him.

As a matter of fact, he was more concerned about Helen’s wellbeing. This entire situation couldn’t have been easy for her: seeing her mother stay with Roylott and feeling unable to stop her, losing her sister… John could only imagine how upsetting the news would be, when they told her that Roylott himself had killed Julia; and on top of that, that he, too, was now dead. John didn’t think Roylott was someone Helen would grieve, with how much harm he had caused her family. But still, he knew the news would be shocking.

“Helen, um…” he hesitated. “Roylott’s dead.”

Helen looked up. “D- Dead?”

“Indeed”, said Sherlock. “He was the one who killed Julia. Upon realising this, we went after him, but he attacked us, and in defending ourselves, we had to kill him.”

Helen shook her head, confused. “It can’t be. I told you, I saw a… a black cape! _That’s_ what killed my sister!”

“It was”, Sherlock replied. “Mr Roylott was a smuggler; he traded illegal magical creatures. The cape you saw was one of them. It’s called a… Lethifold, was it, John?”

“Yeah”, John said. “Most wizards describe it as a black cloak, so it’s not strange that you thought that’s what you saw. This thing… it, well…” he sighed. There was no way to put it nicely, he supposed. “It suffocates people and eats them”, he said. “It’s one of the most dangerous beasts in the world.”

Helen put a hand over her mouth, her eyes wide open in horror. “You mean that… Oh, Julia”, she sobbed, burying her head in her hands.

John went into the kitchen and fetched her a glass of water. “Here”, he said, handing it to her. “I could also give you something to help you sleep, if you want”, he offered. He supposed Helen was too anxious to get any sleep at all.

Helen nodded, taking a sip. “Thank you”, she managed. She stayed silent for a few minutes, still trying to absorb the information. “What I don’t understand is”, she said after a while, “why would he want to kill her?”

John looked at Sherlock, silently asking him to respond. He couldn’t see Roylott’s motives either.

“Simple”, said Sherlock. “Your stepfather was abusive and controlling. He managed to stay married to your mother for quite a long time; even though she had long fallen out of love with him. He liked being in control - making her scared of leaving him, cutting her off from others. 

“However, Julia was a threat to that control, and she was starting to succeed. You said that she and your mother were settling their differences. Now, Julia was very determined to make her leave Roylott. She wouldn’t have been the one to give in. No, it was your mother who was finally taking Julia’s advice.

“Roylott had always known that this was a possibility. So he made a plan: to keep Julia close, in case he should need to get her out of the way. He gave her this flat, just above your mother’s practice, because it was very strategically located. He had easy access to the practice, so he used his magic to hide his beasts there; and then, when he realised that Julia had finally convinced Mrs Stoner to leave him, he let one of the beasts out through the back window and into Julia’s bedroom. It was a flawless plan: the area the windows lead to is closed; it can’t be seen from the streets or alleys. There would’ve been no witnesses at all.”

“Except me”, Helen murmured.

“Indeed”, Sherlock confirmed. “He wasn’t counting on that. But that’s not all”, he commented. “He didn’t just want no witnesses; he also left no evidence. The Lethifold ate Julia quickly, leaving no trace of her or of its presence. And since Julia wasn’t a witch, the case would be handled by Muggle authorities, who couldn’t have possibly considered magic as a possibility.”

“Sorry, _what_ authorities?” Helen interrupted.

“Muggle”, said John. “It means non-wizard people. Wizarding communities aren’t really involved with Muggles”, he explained. “We have our own government, schools, police force…”

“Oh. Okay”, Helen nodded.

“On top of that”, Sherlock continued, “he made sure Scotland Yard wouldn’t get too deep into this case. At first I thought he had bribed some officers”, he explained, “but now I wonder if he put some spell on them. John? Any ideas?”

John pursed his lips, thinking. “I dunno”, he sighed. “Perhaps… a Confundus Charm, or the Imperius Curse”, he suggested.

Sherlock rolled his eyes. “And that means…?”

John chuckled. “The Confundus Charm would make them confused and probably forget about the case for a while. And the Imperius Curse is… much worse”, he said. “He’d have complete control of their actions; he could force them to close the case or something if he wanted to.”

Sherlock smirked. “Brilliant”, he whispered.

“Sherlock”, John said, warningly.

“In any case”, Sherlock went on, as though he were pretending he hadn’t just said ‘brilliant’, “it was a happy coincidence for Roylott that you moved here after you and your girlfriend broke up. That way, he would be able to kill you easily if you tried to finish Julia’s plans to make your mother leave him, or if you ever got the police to reopen Julia’s case”, he explained. “That’s why tonight, seeing that you had come to us, he let the Lethifold into your bedroom, thinking you were there. He repeated the operation.”

John didn’t say it out loud, but he had to admit, it _was_ brilliant. Roylott had considered every little detail. He had planned Julia’s murder carefully and coldly. It was, magical or not, at least a 9 in Sherlock’s scale.

He cleared his throat. “We should, um… we should probably get back downstairs”, he said.

Helen smiled at them, somewhat tiredly. “Alright”, she said.

“Are you sure you’ll be okay?” John asked. “Do you want us to stay, or call someone?”

“Don’t worry. I’m okay”, she assured. “It will never be easy to live without Julia. But now that I know what happened to her, at least I’ve found a little peace. It’s not perfect”, she said, “but it’s better than nothing.”

They said goodbye, and after she had paid them, John and Sherlock left her flat and climbed down the stairs. Sherlock got to the practice door first. He stood there, waiting for John before pushing it open; and then, out of the blue, John chuckled.

“What?” asked Sherlock. “What is it?”

“You’re bloody brilliant”, John said. He approached Sherlock slowly, standing just a few centimetres from his face. Tiptoeing, he planted a soft kiss upon his lips. “D’you know that?” he asked under his breath, looking into Sherlock’s eyes.

Sherlock smiled, cupping John’s face and kissing him back. “I know”, he said when they pulled apart. “Though”, he smirked, teasingly, “this case would've been much easier if you’d just told me you were a wizard before.”


	8. Epilogue

**Notes for the Chapter:**

> Thank you to Kittie for britpicking; to Steph for betaing; and to you, for reading till the end ❤

Loptson had not been happy that they’d left without telling him. He had bombarded them with questions as soon as they’d crossed the door: "Where have you been?" and "Are you mad? We’ve been looking everywhere for you!" and "You could’ve said something."

John’s only answer had been a forced smile and a hoarse, “Yeah, sorry.”

There had also been good news, though. They had managed to contain the Lethifold; Officer Naja had just taken it to the Ministry. And Officer Fernández had recovered Sherlock’s mobile, too.

“A Niffler was playing with it”, she had said. Sherlock had simply nodded, silently deducing that, for some reason, Fernández apparently thought  _ snifflers _ were cute.

“Oh, one more thing before you go”, Loptson had said. “Mind explaining what I’m supposed to tell my bosses when they ask about Mr Roylott’s death?” he had inquired, a bit irritated.

John had gone stiff, not knowing what to answer. But thankfully, Sherlock had been quicker to respond, saying, “I was just defending John. Roylott had disarmed him, and he would’ve killed us both if I hadn’t shot him.”

“I should bring you both in for an inquiry, you know? But…” Loptson had sighed. “I understand if you don’t want that”, he had said to John; and Sherlock could tell that Loptson knew something he didn’t. “So I’ll just say he was dead when you found him, or something. Besides”, he had smiled, patting John on the shoulder, “I owe you one, don’t I? From ‘96?”

John had actually smiled with relief now. “Thanks, Sept.”

Loptson had smiled back. “Take care.”

With that, John and Sherlock had left and hailed a cab. The ride back home had been quiet, awkward. Neither of them had spoken a word. 

Now they sat in their living room, face to face. With a flick of John’s wand, two glasses of whiskey appeared on the coffee table.

They had a long conversation ahead of them. This would be a long night indeed.

**FIN.**


End file.
